This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. The subproject and investigator (PI) may have received primary funding from another NIH source, and thus could be represented in other CRISP entries. The institution listed is for the Center, which is not necessarily the institution for the investigator. We have identified a group of six NLRP (NLR family, pyrin domain containing) genes that are specifically expressed in the oocyte and early preimplantation embryos in rhesus macaques. Mouse NLRP5 has been demonstrated to be essential for embryogenesis beyond the 2-cell stage, and human NLRP7 was identified as the first maternal effect gene as the mutations of which have been linked to various forms of reproductive wastage. However, functions of other NLRP family members are not known. Our preliminary data in nonhuman primates, along with recent findings in rodents and domestic animals, suggest that these oocyte-specific NLRP genes play important roles during oogenesis and early embryo development in mammals. The purpose of this project is to reveal the functions of selected oocyte-specific NLRPs in mice and rhesus macaques. The specific aims are to: (1) characterize in vivo functions of mouse NLRP4A and 9B using knockout mouse models;(2) demonstrate the in vitro postovulatory roles of selected NLRP genes (mouse Nlrp4a, 5 and 9b;macaque NLRP4, 5 and 9) in mouse and macaque oocytes;(3) identify and analyze factors that interact with selected NLRP proteins in mouse and macaque oocytes. NLRP proteins contain a pyrin domain (PYD), a NACHT, and a leucine rich repeat (LRR) domain;both the PYD and LRR mediate protein-protein interactions. Experimental designs include generation and analysis of gene knockout mouse models, RNA interference (RNAi) in mouse and monkey oocytes, and application of yeast two-hybrid system in the mouse and macaque oocyte. We have demonstrated that NLRP5 is required for the oocyte-to-embryo transition in nonhuman primates. Functional studies with Nlrps 4a and 9b in mice, and NLRPs 4 and 9 in monkeys are still ongoing.